Hair loss - red flag symptoms

 Hair on the scalp grows at a rate of about 1cm a month, and each individual hair continues to grow for up to about 6 years. The cycle of hair growth occurs in three stages: anagen (growth), catagen (transition), and telogen (rest). A loss of at least 50–100 hairs a day is regarded as completely normal. Some gradual hair loss with age can be normal.

Hair loss can happen gradually or suddenly. It may recover or remain permanent.

Red flag symptoms

• Complete hair loss
• Sudden hair loss
• No apparent external cause
• Excessive unexplained tiredness
• Weight loss
• Suspected kerion

Causes

The most common type of hair loss is a gradual thinning, starting at the top of the head. Hair growth and loss can be affected by:

• Hormonal factors such as pregnancy, childbirth, menopause, polycystic ovaries and thyroid problems.
• Medications, for example for cancer, arthritis, contraception, depression, diabetes, heart problems, hypertension and gout.
• Medical conditions including diabetes and autoimmune diseases, for example, hyperthyroidism.

As well as prescribed medication, consider accidental or deliberate poisoning. Anaemia or excessive weight loss can be relevant if there is a lack of iron, protein, zinc, fatty acids or vitamins.

A sudden loss of hair through an emotional or physical shock typically becomes apparent several months after the event and usually results in handfuls of hair coming out. It tends to cause general thinning of the hair overall, rather than any bald patches. Hair often recovers again, but possibly not fully.

Sometimes habitual tugging, pulling and plucking (trichotillomania) of hair can be an expression of psychological distress, occasionally even with a denial that it is happening.

Alopecia areata
Localised hair loss (alopecia areata) is likely to be an autoimmune process, which can cause scalp itchiness, redness and tenderness. Local fungal infection can create a similar pattern as alopecia areata.

Traction alopecia
Traction alopecia is a mechanical issue, when hair styling – ponytails, braids – pulls the hair frequently and too hard. Hot oil hair treatments and some colouring or hair dyes may also cause inflammation of the hair follicles, which can lead to scarring and subsequent permanent hair loss.

Androgenetic alopecia
'Physiological' hair loss may follow the male pattern (gradually receding hairline and thinning on top of the scalp) or female pattern (general thinning) and typically has a strong genetic component. It can occasionally lead to complete hair loss, in some cases not only on the scalp.

In alopecia totalis there is total loss of scalp hair and alopecia universalis is the loss of all body hair.

Possible causes

• Tinea capitis
• Anaemia
• Hypothyroidism
• Lupus
• Lichen planus
• Medication side-effects, for example, anabolic steroids
• Trauma and 'shock fallout'
• Severe eating disorder
• Telogen effluvium
• Trichotillomania
• Traction alopecia
• Alopecia areata

Assessment

Establish the timeline of observed hair loss and the quantity and distribution of it. Check medication changes, stresses or any physical impacts. Be mindful of universal red flags, such as unexpected weight loss, behaviour change or metabolic changes.

Ask whether the patient has experienced hair loss before. If so, what was the outcome? What are their ideas, concerns and expectations?

Look out for any apparent irritation, scarring or a kerion (a thickened, inflamed, pus-filled area over the scalp). This is a complication in severe tinea capitis.

A kerion is a dermatological emergency. Only prompt treatment with systemic steroids will prevent the destruction of the hair follicles and inevitable permanent hair loss.

Consider some baseline investigations including FBC, U&E, LFTs, TFT, ferritin, HbA1c and inflammatory markers.

Management

Unless there is a clear reversible cause for the hair loss, the treatment options are often limited. Referral for a second opinion may be useful to confirm the diagnosis and to further inform cosmetic management options.

Treatments (although not available on the NHS ) include topical minoxidil and off-license finasteride at a dose of 1mg once daily. Both options need to be used for a minimum of 6 months to assess effectiveness. Finasteride should not be used in women.

Alopecia areata requires referral if >50% of the scalp is affected. Treatments such as topical corticosteroids, intralesional steroids, topical dithranol or minoxidil may be considered.

Rates of recurrence are often high, but spontaneous resolution can also be seen in up to 80% of cases.

Commercial products such as tonics or supplements, and surgical options including hair transplants are, in many cases, very expensive and may not achieve the desired results.